THE CHEMICAL VARIATION OF MOLDAVITE TEKTITES - SIMPLE MIXING OF TERRESTRIAL SEDIMENTS

To test different hypotheses of moldavite formation, a major and trace -element study of 25 moldavite tektites and Sm-Nd isotope measurement of three moldavite tektites was completed. The samples were selected f rom the classical substrewnfields and the newly described locations in Lusatia (Saxony, Germany). Samples with unusual bulk composition were also included. The results confirm earlier studies that the variation in the chemical composition can be explained by single impact and thr ough incomplete mixing of at least three lithographical components dom inated by one of the three minerals or mineral groups: dolomite, clay minerals and quartz. An additional endmember, possibly a rare Earth's mantle component, containing high Co, Cr and Ni concentrations is also needed to explain the observed variations in compatible elements of s ome tektites. Volatile element abundances are low but not necessarily the result of selective volatilization.